Northstar Engines and System Technical Discussion Discussion, XLR's N* VVT rumble on startup and engine light. in Cadillac Engine Discussion; out of 5 cold starts in 1 my engine makes a shutter noise for a few seconds and then dissapears, ...
out of 5 cold starts in 1 my engine makes a shutter noise for a few seconds and then dissapears, the engine light comes on due to this after a few days and at my dealer I got the impression they are guessing the problem...
Sometimes I hear a squilling sound as well that dissapeared after good WOT sessions.
The engine is widely used like it should be and runs very smooth, I tried octane boosters, carburator/injector cleaners etc. but no changes so far,
only a white water vapour smoke sometimes with the cleaner.
Re: XLR's N* VVT rumble on startup and engine light.
Don't try anymore of the additive stuff. If you can get a hold of an OBDII scanner (most car parts stores scan your car for codes free) that would send you in the right direction as far as "codes" and might actually point you right to your problem.
The squilling could be a belt.
Could you elaborate more on the shutter sound? Where does it sound like its coming from?